Extreme wind events or conditions, such as wind gusts, are a common source of damage to modern wind turbine generators (WTGs). For example, if the blades of a WTG are pitched optimally to maximize rotational speed and/or aerodynamic torque and, therefore, increase power production, a sudden gust of wind could drastically increase loading on the blades, perhaps beyond design limitations. Thus, in many modern wind parks, each WTG in the park operates conservatively with a large robustness margin as a precaution against the possibility of an extreme wind event. However, such extreme wind events are relatively infrequent at many wind parks. Consequently, the WTGs of many modern wind parks operate inefficiently for much of the time to avoid the relatively rare possibility of damage that could be sustained due to extreme wind events.
U.S. Patent Application Publication Number 2007/0124025 (the '025 patent publication) describes a system in which a first wind turbine or turbine group in a wind park measures wind speed and direction and a central data processing unit predicts load impact on wind turbines downstream from a first wind turbine or turbine group. Control signals are then generated to reduce power of the downstream wind turbines to minimize extreme load impact. However, because wind frequently changes directions, a wind turbine might be downstream with respect to other wind turbines at one moment but switch to being upstream a moment later. Thus, it would appear that to accommodate wind direction changes, the system described in the '025 patent publication would in practice actually need to significantly limit the number of turbines that can receive the control signal to minimize extreme load impact. More specifically, it appears that the only turbines that can benefit from such a system must always be downstream with respect to at least one other turbine that monitors the wind speed and direction. Accordingly, the benefits the system of the '025 patent publication purportedly provides would in practice be quite limited.
In addition, the downstream turbines that receive controls signals to minimize extreme load impact do not appear to differ from the upstream turbine(s) that measure wind speed and direction. Thus, the downstream turbines do not appear to be designed to take advantage of their protected condition.